From Observation, user account deleted from other DC is not replicated to this particular DC.

If this is just a child domain controller, I could have slept well last night already~ What make it worse is that under my enterprise AD, the one having the issue is my DC holding my RID and PDC emulator roles~!! Which some people will know them as part of the Flexible Single Master Operations (FSMO) roles.

How to resolve the issue? (preferred solution for me)

One of the Domain Controller under one of my Child Domain is having AD Database Corruption

The Domain Controller is holding on to RID and PDC emulator roles

There are 3 other Domain Controller where one is holding on to the Infrastructure Master role and the other 2 are the bridgehead servers

For me, I will always play safe where I will not attempt to repair my AD database as this is one method that one should never try unless the DC is the only domain controller in the forest (no child domain) and you never backup your system state regularly!

For my situation, I will perform the following steps:

Backup whatever data is on the DC that is having the issue

Record down any special configuration such as DNS forwarding or even WINS

Why not the one with infrastructure Master? It is not preferred but if one has no choice, you can use it too. But remember to make it a GC first for the meanwhile.

Why not transfer but seize? You can try but it should not work (For me, dun work). And think carefully, AD Database on that DC is already corrupted, you want to transfer the roles and DC-demote it? Better not, treat the server as if it is having OS Corruption instead. One should not risk the fact that the corrupted data will spread to other DC(s).

Why not disable replication of the server and try to force dc-promote? For me, I have timeline to meet, since I will treat it as a case of OS corruption, I will not waste time to perform that. I will just take the DC offline.